Exhaust manifold for multi-cylinder engine

ABSTRACT

Disclosed is an exhaust manifold for engaging with a plurality of exhaust ports of a multi-cylinder engine for guiding an exhaust gas discharged out of from the multi-cylinder engine. The exhaust manifold includes a plurality of primary conduits and a secondary conduit. Each of the primary conduits includes inlet and exit end portions. Each of the inlet end portions is capable engaging with a corresponding exhaust port. The secondary conduit includes at least one inlet port and at least one exit port. The exit end portions of each of the primary conduits converges with the at least one inlet port to configure a passageway. With the convergence of each of the exit end portions port with the at least one inlet port, there is gradual increase in a cross sectional area of the passageway for guiding the exhaust gas to be discharged out from the multi-cylinder engine.

FIELD OF THE INVENTION

The present invention generally relates to an exhaust manifold for an internal combustion engine, and more particularly, to an exhaust manifold of a multi-cylinder internal combustion engine having a plurality of exhaust ports.

BACKGROUND OF THE INVENTION

Multi-cylinder engines are capable of generating power that is utilized for various purposes, such as for accelerating automobiles and operating power plant equipment. A multi-cylinder engine includes multiple cylinders, such as four cylinders, six cylinders and eight cylinders. Each cylinder of the multiple cylinders includes intake ports and exhaust ports. The intake ports are adapted to intake fresh air, fuel or a combination thereof into the multiple cylinders for enabling a combustion process inside the multiple cylinders in order to generate the power. After combustion process, residual gas is produced, which is released out through the exhaust ports of the multiple cylinders. More particularly, each of the exhaust ports is connected to an exhaust pipe of the multi-cylinder engine via an exhaust manifold for guiding the residual gas out of the multi-cylinder engines.

The exhaust manifold collects the residual gas from the exhaust ports and delivers it to the exhaust pipe of the multi-cylinder engine. Generally, the exhaust manifold includes multiple pipes and a collector. The multiple pipes are coupled to a collector to configure the exhaust manifold. Coupling between the multiple pipes and the collector is in such a manner that the multiple pipes are perpendicular with respect to the collector.

When such exhaust manifold is in use, each of the multiple pipes is connected to corresponding exhaust ports of cylinders of the multi-cylinder engine, which guides the residual gas out of the multi-cylinder engines. The perpendicularity of the multiple pipes causes an acute change in a direction of flow of the residual gas in the exhaust manifold, thereby reducing velocity of flow of the residual gas. Reduction in velocity of the flow of the residual gas results in accumulation of the residual gas at any one portion in the collector, thereby causing a back-pressure and reducing overall performance of the multi-cylinder engine.

Further, the cross-section of the collector remains constant through out a length of the collector. The constant cross-section barricades smooth flow of the residual gas, which increases the effect of the back pressure in the exhaust manifold.

Accordingly, there is a need of an exhaust manifold for a multi-cylinder engine that smoothen a flow of a residual gas. Further, there is a need of an exhaust manifold for a multi-cylinder engine that is capable of reducing back pressure therewithin in order to increase the overall performance of the multi-cylinder engine.

SUMMARY OF THE INVENTION

In view of the forgoing disadvantages inherent in the prior-art, the general purpose of the present invention is to provide an exhaust manifold for a multi-cylinder engine that is configured to include all advantages of the prior art, and to overcome the drawbacks inherent in the prior art.

An object of the present invention is to provide an exhaust manifold for a multi-cylinder engine that is capable of smoothing a flow of an exhaust gas exiting from multiple exhaust ports of the multi-cylinder engine.

Another object of the present invention is to provide an exhaust manifold for a multi-cylinder engine that is capable of reducing back pressure generated there within.

To achieve the above objects, in an aspect of the present invention, an exhaust manifold for a multi-cylinder engine is provided. The exhaust manifold is capable of being engaged with a plurality of exhaust ports of a multi-cylinder engine for guiding an exhaust gas to be discharged out of from the multi-cylinder engine. The exhaust manifold comprises a plurality of primary conduits and a secondary conduit. Further, each of the plurality of the primary conduits comprises an inlet end portion and exit end portion. Each inlet end portion is capable of being engaged with a corresponding exhaust port of the plurality of exhaust ports. Furthermore, the secondary conduit comprises at least one inlet port and at least one exit port. Each exit end portion of the plurality of primary conduits converges with the at least one inlet port to configure a passageway therebetween. With the convergence of each of the exit end portion port with the at least one inlet, a cross sectional area of the passageway gradually increases. The gradual increase in the cross sectional area of the passageway facilitates smooth outlet of the exhaust gas from the exit port of the secondary conduit, thereby guiding the exhaust gas to be discharged out from the multi-cylinder engine.

This together with the other aspect of the present invention, along with the various features of novelty that characterized the present invention, is pointed out with particularity in the claims annexed hereto and forms a part of the present invention. For a better understanding of the present invention, its operating advantages, and the specified object attained by its uses, reference should be made to the accompanying drawings and descriptive matter in which there are illustrated exemplary embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages and features of the present invention will become better understood with reference to the following detailed description and claims taken in conjunction with the accompanying drawings, wherein like elements are identified with like symbols, and in which:

FIG. 1 illustrates a perspective view of an exhaust manifold, according to an exemplary embodiment of the present invention; and

FIG. 2 illustrates a perspective view of an exhaust manifold, according to another exemplary embodiment of the present invention.

Like reference numerals refer to like parts throughout the description of several views of the drawings.

DETAILED DESCRIPTION OF THE INVENTION

For a thorough understanding of the present invention, reference is to be made to the following detailed description, including the appended claims, in connection with the above-described drawings. Although the present invention is described in connection with exemplary embodiments, the present invention is not intended to be limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The term “top”, “bottom” and the like, herein do not denote any order, elevation or importance, but rather are used to distinguish placement of one element over another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

The present invention provides an exhaust manifold for being engaged with a plurality of exhaust ports of a multi-cylinder engine for guiding an exhaust gas to be discharged out from the multi-cylinder engine. The exhaust manifold comprises a plurality of primary conduits and a secondary conduit. More particularly, the plurality of the primary conduits converges with the secondary conduit to configure the exhaust manifold. The plurality of primary conduits of the exhaust manifold engages with the plurality of exhaust ports of the multi-cylinder engine. Upon engaging, the plurality of primary conduits guides the exhaust gas that is discharged out from the plurality of exhaust ports of the multi-cylinder engine, and provides exit to the exhaust gas from an exit port of the secondary conduit.

Referring now to FIG. 1, an exhaust manifold 100 is shown, according to an exemplary embodiment of the present invention. The exhaust manifold 100 is capable of being engaged with a plurality of exhaust ports (not shown) of a multi-cylinder engine (not shown) for guiding an exhaust gas to be discharged out from the multi-cylinder engine. More particularly, the exhaust manifold 100 comprises a plurality of primary conduits 102 (herein after referred to as ‘primary conduits 102’), and a secondary conduit 104. Further, each of the primary conduits 102 includes an inlet end portion 106 and an exit end portion 108. The inlet end portion 106 facilitates the engagement of the exhaust manifold 100 with the plurality of exhaust ports of the multi-cylinder engine. More specifically, each of the inlet end portion 106 is capable of being engaged with a corresponding exhaust port of the multi-cylinder engine for receiving the exhaust gas discharged out from the cylinders of the multi-cylinder engine. In one embodiment, the primary conduits 102 have a circular cross section that engages with the plurality of exhaust ports of the multi-cylinder engine. Further, the secondary conduit 104 includes at least one inlet port, which is shown as various inlet ports 110, and at least one exit port 112.

The inlet ports 110 of the secondary conduit 104 are provided at various portions along a length of the secondary conduit 104 as shown in FIG. 1. Further, the exit end portion 108 of the primary conduits 102 converge with the inlet ports 110 to configure a passageway 114. More particularly, each of the exit end portions 108 converges with a corresponding inlet port 110 to configure the passageway 114 with increase in a cross sectional area, which is shown as various cross sectional area 116. The cross sectional area 116 of the passageway 114 increases gradually along a length of the secondary conduit 104. On convergence of the exit end portion 108 with the inlet ports 110, the exhaust gas from the primary conduits 102 that is received from the exhaust port of the multi-cylinder engine passes to the exit port 112 through the passageway 114. The exit port 112 is preferably of a circular cross-section that engages with an exhaust pipe of the multi-cylinder engine. The engagement therebetween is described further. Further, the convergence between the exit end portions 108 with the inlet ports 110 is in a manner such that a curve is formed at each convergence, configuring an oval cross section of the passageway 114. The oval cross section and the gradual increase in the cross sectional area 116 of the passageway 114 enables smooth flow of the exhaust gas from the passageway 114.

In one embodiment, the cross sectional area 116 of the passageway 114 may gradually increases in a manner such that a major axis of the cross sectional area 116 increases by ½ inch at each convergence. For example, the major axis of the cross sectional area 116 at a first convergence may be 1¼ inches (shown as a first major axis ‘a’), which gradually increases at a second convergence by ½ inch and results in the major axis of the cross sectional area 116 to be of 1¾ inches (shown as a second major axis ‘b’). Similarly, the major axis at a third convergence, and at a fourth convergence, may be of 2¼ inches and 2¾ inches, respectively. The major axes at a third convergence, and at a fourth convergence are, respectively, shown as a third major axis ‘c’, and a fourth major axis ‘d’. The increase in the cross sectional area 116 results oval cross section of the passageway 114, which enables smooth flow of the exhaust gas in a forward direction towards the exit port 112 of the secondary conduit 104. Further, the exit port 112 may be more than one for fast outlet of the exhaust gas. The flow of the exhaust gas in the forward direction eliminates accumulation of the exhaust gas at any portion of the exhaust manifold 100 reducing the probability of causing a back pressure in the exhaust manifold 100.

Further, in the exemplary embodiment as shown in FIG. 1, the exhaust manifold 100 includes four primary conduits, such as primary conduits 102. The four primary conduits as shown in FIG. 1 are for a four-cylinder engine. Similarly, the exhaust manifold, such as the exhaust manifold 100 may include six or eight primary conduits. The exhaust manifold with six primary conduits may be suitable for a six-cylinder engine, and the exhaust manifold with eight primary conduits may be suitable for an eight-cylinder engine. Further, the number of primary conduits 102 may vary depending upon the number of cylinders in the multi-cylinder engine.

The primary conduits 102 and the secondary conduit 104 are made of materials, such as cast iron or stainless steel. However, it will be evident to a person skilled in the art to make the primary conduits 102 and the secondary conduit 104 from any other material.

The exhaust manifold 100 further comprises a plurality of attaching mechanisms 118. Each of the attaching mechanisms 118 are deposed on each of the inlet end portion 106 of the primary conduits 102. The attaching mechanism 118 enables engagement of the exhaust manifold 100 with the plurality of exhaust ports of the multi-cylinder engine. In one embodiment, the attaching mechanisms 118 are flanges. The flanges are disposed at the inlet end portions 106. A flange of the flanges includes through-holes 120. Similar to the flange at the inlet end portion 106, there is a flange disposed on each of the plurality of exhaust ports (not shown). The flange disposed on each of the plurality of exhaust ports includes through-holes (not shown). The through-holes 120 match with the through-holes of the plurality of exhaust ports to accommodate threaded nut-bolt assembly to couple the plurality of exhaust ports with the primary conduits 102. Further, a sealing member (not shown), such as a gasket may be utilized between the flanges of the plurality of exhaust ports and the primary conduits 102 for preventing leakage.

The secondary conduit 104 includes a coupling mechanism 122 disposed on the exit port 112 for coupling the exhaust manifold 100 with the exhaust pipe. In one embodiment, the coupling mechanism 122 is a flange similar to the flange of the inlet end portion 106. The flange includes through-holes (not shown). The through-holes match with the through-holes of a flange of the exhaust pipe to accommodate threaded nut-bolt assembly to provide coupling therebetween. Further, a sealing member (not shown), such as a gasket may be utilized therebetween for preventing leakage.

Referring now to FIG. 2, an exhaust manifold 200 according to another exemplary embodiment of the present invention is illustrated. The exhaust manifold 200 includes a plurality of primary conduits 202 (hereinafter referred to as ‘primary conduits 202’), and a secondary conduit 204. Further, similar to the primary conduits 102, each of the primary conduits 202 includes an inlet end portion 206 and an exit end portion 208. The inlet end portion 206 facilitates the engagement of the exhaust manifold 200 with the plurality of exhaust ports of the multi-cylinder engine. Similar to the secondary conduit 104, the secondary conduit 204 includes at least one inlet port, shown as various inlet ports 210, and at least one exit port, such as exit port 212. The exit end portion 208 of each of the primary conduits 202 converge with the inlet ports 210 at an end portion of the secondary conduit 204 configuring a passageway 214 with a gradual increase in a cross sectional area 216 of the passageway 214.

In one embodiment, the cross sectional area 216 of the passageway 214 may gradually increases in a manner such that a major axis of the cross sectional area 216 increases by ½ inch at each convergence. For example, the major axis of the cross sectional area 216 at a first convergence may be ¼ inches (shown as a first major axis ‘p’), which gradually increases at a second convergence by ½ inch and results in the major axis of the cross sectional area 216 to be of 1¾ inches (shown as a second major axis ‘q’). Similarly, the major axis at a third convergence, and at a fourth convergence, may be of 2¼ inches and 2¾ inches, respectively. The major axis at a third convergence and at a fourth convergence are, respectively, shown as a third major axis ‘r’, and a fourth major axis ‘s’. The increase in the major axis of the cross sectional area 216 of the passageway 214 enables smooth flow of the exhaust gas in a forward direction towards the exit port 212 of the secondary conduit 204. The flow of the exhaust gas in the forward direction eliminates accumulation of the exhaust gas at any portion of the exhaust manifold 200, thereby reducing the probability of causing a back pressure in the exhaust manifold 200.

Further, in one embodiment the passageway 214 is oval in cross section of the secondary conduit 204. The oval cross section of the passageway 214 enable smooth flow of the exhaust gas without any obstacles. Furthermore, the primary conduits 202 include a plurality of attaching mechanisms 218, similar to the attaching mechanisms 118, for attaching the primary conduits 202 to the plurality of exhaust ports of the multi-cylinder engine. Moreover, the secondary conduit 204 includes a coupling mechanism 220 disposed on the exit port 212 for coupling the secondary conduit 204 with the exhaust pipe for passing on the exhaust gas further.

The exhaust manifolds, such as the exhaust manifolds 100 and 200, of the present invention provide following advantages. The exhaust manifolds are capable of facilitating gradual turning and smoothing a flow of the exhaust gas exiting from a plurality of cylinders of the multi-cylinder engine. Further, the exhaust manifolds are capable of reducing back pressure generated therewithin.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. 

1. An exhaust manifold for being engaged with a plurality of exhaust ports of a multi-cylinder engine for guiding an exhaust gas discharged out from the multi-cylinder engine, the exhaust manifold comprising: a plurality of primary conduits, each of the plurality of primary conduits having an inlet end portion and an exit end portion, each inlet end portion capable of being engaged with a corresponding exhaust port of the plurality of exhaust ports of the multi-cylinder engine; and a secondary conduit having at least one inlet port and at least one exit port, each exit end portion of the plurality of primary conduits converges with the at least one inlet port to configure a passageway, wherein with each convergence of the exit end portion with the at least one inlet port a cross sectional area of the passageway gradually increases for facilitating an outlet to the exhaust gas from the at least one exit port of the secondary conduit, thereby guiding the exhaust gas to be discharged out from the multi-cylinder engine.
 2. The exhaust manifold of claim 1, further comprising a plurality of attaching mechanisms, an attaching mechanism of the plurality of attaching mechanisms disposed on the each inlet end portion of the plurality of primary conduits for engaging the each inlet end portion with the corresponding exhaust port of the plurality of exhaust ports of the multi-cylinder engine.
 3. The exhaust manifold of claim 1, further comprising a coupling mechanism disposed at the at least one exit port for coupling with an exhaust pipe of the multi-cylinder engine.
 4. The exhaust manifold of claim 1, wherein each exit end portion of the plurality of primary conduits converges with the at least one inlet port at an end portion of the secondary conduit to configure the passageway.
 5. The exhaust manifold of claim 1, wherein the each exit end portion of the plurality of primary conduits converges with the at least one inlet port along a length of the secondary conduit to configure the passageway.
 6. The exhaust manifold of claim 1, wherein the passageway is of an oval cross section.
 7. The exhaust manifold of claim 1, wherein the at least one exit port is of a circular cross section.
 8. The exhaust manifold of claim 1, wherein each of the plurality of primary conduits is of a circular cross section.
 9. The exhaust manifold of claim 1, wherein the plurality of primary conduits is made of at least one of cast iron and stainless steel.
 10. The exhaust manifold of claim 1, wherein the secondary conduit is made of at least one of cast iron and stainless steel. 